Three cylinder convertible printing press



Aug. 31, 1965 R. K. NORTON ETAL 3,203,345

' THREE CYLINDER CONVERTIBLE PRINTING- PRESS Filed May 2, 1961 4 Sheets-Sheet 1 Fl G. 5

INVENTOR.

ROB K. NOR HOWAR .PRITCHA BY ATTORNEY 3 1965 R. K. NORTON ETAL 3,203,346

THREE CYLINDER CONVERTIBLE PRINTING PRESS Filed May 2. 1961 4 Sheets-Sheet z 20 I9 LITHOGRAPHIC 24 OFFSET C llqm fljl l l 42 l 4 46 7 Ila FIG. 2

DIRECT LETTER PRESS "b INVENTOR ROBERT K. NORTON HOWARD A. PRITCHARD ATTOR Y Aug. 31, 1965 R. K. NORTON ETAL 3,203,345

THREE CYLINDER CONVERTIBLE PRINTING PRESS 4 Sheets-Sheet 5 Filed May 2. 1961 -r 1, 1965 R. K. NORTON ETAL 3,203,346

THREE CYLINDER CONVERTIBLE PRINTING PRESS Filed May 2, 1961 4 Sheets-Sheet 4 ROBERT K. NORTON BYHOWARD A.PRITCHARD ATTORNEY IN VEN TOR.

United States Patent 3,203,346 THREE CYLINDER CONVERTIBLE PRINTING PRESS Robert K. Norton, Twinshurg, and Howard A. Pritchard,

Hiram, Ohio, assignors to Harris-Intertype Corporation,

Cleveland, Ohio, a corporation of Delaware Filed May 2, 1961, Ser. No. 107,197 6 'Claims. (Cl. 101217) This invention relates generally to rotary printing presses, and in particular to a rotary printing press adapted to be convertible for use with different printing processes.

The principal object of our invention is to enable the conversion of a rotary printing press for use with any of a plurality of different printing processes in which conventional thin, flexible printing plates and flexible blankets may be utilized.

A further object is to provide for such conversion while enabling use of plate clamps and blanket reel rods of conventional design.

Still another object of the invention is to provide for the mounting of a printing plate and a blanket on alternate ones of a pair of cylinders by enabling the simple and easy transfer of plate clamps and blanket reel rods or clamps from one cylinder to the other.

Another object is to provide a cylinder which is capable of interchangeably receiving either plate clamps or blanket reel rods or clamps.

Other objects and advantages will be apparent from the following description in which reference is made to the accompanying drawings.

According to the invention, each of a pair of cylinders is adapted to receive in a gap therein either a blanket mounting means or a plate mounting means, whereby either a flexible substantially incompressible printing plate or a flexible resilient blanket may be mounted on the cylinder. By interchanging the mounting means, the unit can be used to print by the direct letterpress method or by the lithographic offset method as desired.

In the drawings:

FIG. 1 is a simplified elevational view of the threecylinder printing unit which can be easily converted from a lithographic offset printing press to a direct printing letterpress, and vice versa.

FIG. 2 is an enlarged cross-sectional fragmentary view of a pair of cylinders of FIG. 1 showing the parts in their relative positions when the press is adapted to print by the lithographic offset process.

FIG. 3 is a view similar to FIG. 2 with the parts in their relative positions when the press is adapted to print by the direct letterpress process.

FIG. 4 is an elevational view of the cylinders with the parts located as illustrated in FIG. 2, and is taken looking from the left of that figure with the cylinders being in positions of rotation approximately 90 before arriving at the position shown in FIG. 2.

FIG. 5 is an enlarged fragmentary view of the left end of the blanket reel rod of FIG. 4.

FIG. 6 is an enlarged view of the blanket reel rod pawl and ratchet means for locking the blanket reel rod in tensioned position, and is taken looking substantially along the lines 66 of FIG. 4.

FIG. 7 is a view similar to FIG. 1, but taken on a larger scale and illustrating a modification of the invention.

Referring now to FIG. 1, the preferred type of printing unit adapted to incorporate the present invention is shown as comprising an impression cylinder 10, an intermediate cylinder 11, and a third cylinder 12. As will be explained in more detail later, when the printing unit is adapted to print by the lithographic oflset process, the

cylinders 10, 11 and 12 will comprise an impression cylinder, blanket cylinder and plate cylinder respectively of a lithographic printing unit. When used to print by the direct letterpress process, however the cylinders 10, 11 and 12 will comprise a tympan cylinder, plate cylinder and inking cylinder respectively of a letterpress printing unit. For purposes of clarity, since the cylinder 11 will be a blanket cylinder of the lithographic unit and a plate cylinder of the letterpress unit, and since the cylinder 12 will be a plate cylinder of the lithographic unit and an inking cylinder of the letterpress unit, these cylinders 11 and 12 will be designated with the letters a or b, the letter a designating a cylinder when used as a lithographic component, and the letter b being used when comprising a letterpress component. (Note FIGS. 2 and 3 for example.)

Furthermore, since the cylinder 10 will require tympan packing when used in the letterpress printing process, but conventionally does not require such packing when used for lithographic printing, we prefer to construct the cylinder 10 as a tympan cylinder for use with both processes. The cylinder 10 may therefore be designed as shown in the co-pending U. S. application of Robert K. Norton, Ser. No. 22,760 filed April 18, 1960. Since the cylinder 10 comprises only an incidental part of the inventive concept claimed herein, suffice it to say that the cylinder 10 may be of any suitable construction.

The cylinder 12 has located thereabove a conventional inker 13 which includes a plurality of ink form rolls 14. In addition, a lithographic dampening unit 15 is provided on the approaching side of the inker 13 as related to the direction of rotation of the cylinder 12. The dampening unit may be of any construction, and may dampen the plate directly or through certain of the ink form rolls as is well known. For purposes of this invention, it is sufiicient to understand that the dampening unit is mounted to be movable between operative and inoperative positions as shown in dotted and full lines respectively in FIG. 1. When the printing unit is used for printing by the lithographic process, the dampener is made operative and is located in the dotted line position of FIG. 1. When the unit prints by the direct letterpress process, however, the dampener is moved to the right as shown in FIG. 1 to an inoperative position.

Lithographic offset printing unit Let us now assume that the unit described in FIG. 1 is being used for printing by the lithographic offset process. Under such conditions, as can be seen in FIG. 2, the blanket cylinder 11a and the plate cylinder 12a are adapted to run in rolling contact and are preferably provided with bearers 16 and 17 at their respective ends for purposes well understood in the art. Since the cylinder 10 is a tympan cylinder having packing which may be varied in thickness to accommodate stocks of varying thickness, it too is preferably provided with bearers (not shown). A conventional lithographic printing plate 18 is adapted to be mounted on the cylinder 12a by means of a leading edge plate clamp 19 and a trailing edge plate clamp 20, both of which are mounted within a gap 21 in the cylinder. The blanket cylinder 11a has mounted therearound a conventional offset blanket 22 which is used to transfer the image from the plate 18 to paper or other stock passing between the cylinders 10 and 11a. The blanket 22 is preferably provided with a blanket bar 23 at each end thereof. The blanket bars comprise upper and lower strips fastened together by screws in a known manner. The bar 23 at the leading edge of the blanket is locked to the cylinder 11a by a portion of a clamp 24, is wrapped around the blanket cylinder 11a, and is received at its trailing edge by a blanket reel rod 25. Both the clamp 24 and the reel rod 25 are adapted to be mounted in a gap 26 in the periphery of the blanket cylinder. The

blanket is fastened to the reel rod 25 by means of the bar 23 which seats against an abutment and flat produced on the reel rod 25, and is held thereto by means of screws 27 in customary fashion. One end of the reel rod 25 has the usual pawl and ratchet mechanism 28 as illustrated in FIG. 6. The reel rod 25 is capable of being rotated to tension the blanket around the cylinder and is latched in tensioned position by the pawl and ratchet mechanism 28.

In our preferred embodiment, each of the clamps 19, 20 and 24 is adapted to be operated in substantially the same way. Therefore, the plate clamp operation will be described only with reference to the clamp 19. The clamp 19 comprises a bar 29 and a movable jaw 35) which together form the plate receiving and clamping elements. The jaw 30 is capable of being rocked about the rounded heads of a plurality of screws 31. Movement of the jaw 30 of the clamp 19 in a clockwise direction about the rounded heads of the screws 31 (as shown in FIG. 2) is effected by counterclockwise rotation of a camming shaft 32 to the position illustrated. Rotation of the shaft 32 may be accomplished by engaging a pin wrench in a hole 34 in an enlarged portion 35 of the shaft 32. (See FIG. 4.) The parts of the clamp 19 are shown in plate clamping position in FIG. 2. To release the plate 18, the shaft 32 is rotated clockwise until a flat 33 on the shaft 32 is opposite the portion of the jaw 30 engaged by the shaft 32 when in clamping position. At such time, the jaw 30 is opened to release the plate by means of springs (not shown) normally urging the jaw 30 in a counterclockwise direction as viewed in FIG. 2. All of the clamps 19, 20 and 24 are capable of being moved inwardly of their respective gaps by tensioning screws 36 which may be operated by turning knurled heads thereon or using a pin wrench in holes 37 in each head. The screws 36 engage the ends of pins 38 which pass through the bar 29 and engage a filler bar 39 received in a recess 40, the purpose of which will become apparent shortly. The screws 36 function to jack the clamps inwardly of their gaps to tension the plate around the bar 29 is resiliently urged toward the end of the gap by springs 62 at the ends thereof. (See FIG. 4.) Therefore, when the screws 36 are actuated in a direction to relieve the jacking force, the springs will urge the bar 29 leftwarclly as shown in FIG. 2, depending, of course, on the extent of movement of the screws 36.

In order to facilitate the receipt of either a plate or blanket on the cylinders 11 and 12, the cylinders are preferably ground to the same diameter. Since blanket and plate thicknesses are generally different, it is necessary to provide packing 41 under the plate 18.

, The blanket 22 is mounted on the cylinder 11a with its leading edge blanket bar 23 being engaged in a recess 42 of the shape and size of the recess 40 in the cylinder 12a. The trailing edge of the blanket has its blanket bar engaged with the reel rod 25 as mentioned previously and is locked thereto. It will be noted that the clamp 24 on. cylinder 11a has been moved inwardly of the gap in order for the leading edge blanket bar 23 to be inserted in the groove 42. To provide for ease of insertion ofthe leading edge blanket bar 23 in the recess 42, the clamp 24 has machined therethrough a passage 46. A pin may pass through the passage 46 and be engaged with a blind hole 46' in the cylinder body to serve in prying the clamp 24 inwardly of the gap 26 to compress the springs 62 and thus enable ready insertion of the blanket bar. The springs 62 lock the bar 23 in the recess 42 when the prying pin is released. When so locked, the reel rod 25 which then receives the trailing edge bar 23 may be rotated with the pawl and ratchet mechanism 28 providing the necessary latching once the blanket 22 is properly tensioned. The identical structure is used in conjunction with the plate clamp 19 for receiving and clamping a blanket bar 23, as will be seen hereinafter.

With the parts in their positions shown in FIG. 2, the cylinders 11a and 12a are adapted for printing by the lithographic olfset process. It will be noted that the cylinders 11a and 12a are substantially alike in the shape of their gaps and of the recesses 40 and 42, although they are of opposite hand.

Direct letterpress printing unit Referring now to FIG. 3, in which the cylinders 11 and 12 are adapted for printing by the direct letterpress printing process, it will be noticed that the clamps 19 and 24 are in their same relative locations as when they are used for lithographic offset printing. The main difference as compared to FIG. 2 is that the plate clamp 20 and the .reel rod 25 have been interchanged and are now installed on different cylinders. Their manner of functioning remains the same, however. It will be noticed subsequently that the two cylinders 11 and 12 are constructed to interchangeably receive either the plate clamp 20 or the reel rod 25.

In FIG. 3, the blanket 43 comprises a resilient inking surface which is engaged by the ink form rollers 14. Consequently, the blanket 43 is merely an inking surface of the large inking cylinder 12b. In converting the unit from lithographic offset to direct letterpress printing, the filler bar 39 is removed from the recess 40 of the plate cylinder 12a by moving the plate clamp 19 rightwardly. This can be quickly accomplished as described in connection with passage 46 and blind hole 46' for clamp 24. The bar 39 is installed in the recess 42 of the plate cylinder 1112. With the clamp 19 moved sufficiently far to the right in FIG. 3, the leading edge blanket bar 23 may be inserted into the recess 40 in the same fashion as it was previously seated in the recess 42 of the blanket cylinder 11a. The blanket 43 is wrapped around the inking cylinder 12b and has its trailing edge blanket bar 23 engaged with the blanket reel rod 25, as described earlier. The pawl and ratchet mechanism 28 may then be used to tension the blanket 43 and latch the reel rod 25 in tensioned position.

The cylinder 11b is adapted to receive as relief printing plate 44. Packing 45 is provided between the plate 44 and the plate cylinder 11b to bring the plate surface to the proper height. Ordinarily, relief plates of the flexible type disclosed are thicker than the lithographic plates 18 previously mentioned with reference to FIG. 2. Accordingly, the packing 45 should be adjusted to compensate for such dimensional difference. Such packing under any of the plates (or blankets if necessary) may be varied as desired for purposes known to those skilled in the art.

FIG. 4 illustrates the lithographic unit of FIG. 2 looking from the left thereof with the cylinders being rotated C. before reaching the position of FIG. 2. The cylinders are shown with the blanket and plate removed. It will be seen that the clamps 19 and 20 on the cylinder 12a are held in position by gibs or plates 47 at the ends thereof. The gibs 47 are shown as being fastened to the cylinder 12a by means of three screws 48. To remove the clamp 20 from the cylinder 12a for interchanging it with the blanket reel rod 25, the gibs 47 are removed and the clamp 20 lifted from the cylinder. The reel rod 25 is then removed from the cylinder 11a by inward movement of pins 49 (FIGS. 4 and 5) against the action of springs 50 to disengage latch slide rods 51 from coaxial journals 52 through the bearer ends of the cylinder 11a. Pawls 53 fastened to pins journaled in the bearer ends of the cylinders may be removed axially from the cylinder.

With the reel rod 25 and the clamp 20 removed from their cylinders, they may now be interchanged by turning them end for end and each installed in the place previously occupied by the other. The latch slide rods 51 on the reel rod may now be engaged with coaxial journals 55 in the cylinder 12a, and the pins for the pawls 53 may be installed in holes 56 in the right end of cylinder 12a as shown in FIG. 4., At this point, gibs 5'7 holding the clamp 24 in place on the cylinder 11a are removed and installed in position to hold the clamp 19 to cylinder 12a. In addition, the gibs 47 which were formerly on the cylinder 12a, are now located on the cylinder 11a. Tapped holes are shown as being provided for such installation to now hold the clamps 20 and 24 to the cylinder 11a. The springs 62 will also be assembled in their respective positions. With the parts in the positions just described, they will have been converted from printing by lithographic offset to printing by the direct letterpress printing process.

With reference to FIG. 5 which shows the left end of the blanket reel rod 25 on a larger scale than illustrated in FIG. 4, it will be noticed that the pin 49 is capable of sliding the latch slide rod 51 axially against the action of the spring 50, and may be latched inwardly by movement of the pin 49 angularly about the axis of the blanket reel rod to cause it to engage in an ofiset latch groove 58 in the reel rod.

In FIG. 7, we illustrate a modified version of our invention. This modification provides for the blanket clamps and plate clamps to be mounted in individual inserts 5 9 and 60 respectively, with the cylinders 11' and 12' being adapted to receive either one of the inserts in properly aligned condition when they are turned end for end. Each of the inserts 59 and 60 is provided with a channel or U-shaped support which may be fastened by bolts 61 to properly aflix it to a cylinder. It is to be understood that pawl and ratchet mechanism is provided for the insert 59, and such mechanism is preferably carried directly thereby to latch the blanket reel rod .2 5 in tensioned position when required.

While we have described our structure primarily in relation with the direct letterpress and lithographic offset processes, it is obvious that the cylinder arrangement enables use of the structure with still other printing processes. For example, printing may be accomplished by indirect relief printing, commonly called dry oifset. In such case, the clamps and reel rod would be arranged as when printing by the lithographic method. The cylinder '11 would carry a blanket, and the cylinder 12 would carry a relief plate similar to the letterpress relief plate, except for reading opposite to the letterpress plate, as is well known.

Various other modifications and changes may be made in the details of construction, without departing from the spirit and scope of the claims.

Having described our invention, We claim:

1. A three-cylinder convertible printing unit having first, second and third cylinder members arranged for rotation about three parallel axes for printing either directly from a flexible printing plate or by offset from a flexible compressible blanket.

an inker having ink rollers,

said first cylinder member being arranged to support print-receiving material passing through a printing zone,

first mounting mean-s constructed to releasably receive solely the ends of a flem'ble, substantially incompressible printing plate element and including a member movable for tensioning an end of said printing plate element,

second mounting means constructed to releasably receive solely the ends of a flexible, compressible blanket element and including a member rotatable on an axis parallel to the cylinders for tensioning an end of said blanket element,

means on said second cylinder member for securing thereto at least the tension-ing member of either said first or said second mounting means for movement about the axis of said second cylinder member, with the, corresponding element received thereby being adapted .to run in rolling contact with the print-receiving material at said printing zone while supported by said first cylinder member,

and means on said third cylinder member for securing thereto at least the tensioning member of either said first or said second mounting means for movement about the axis of said third cylinder member, with the corresponding element received thereby being adapted to run in rolling contact with said ink rollers and with the element secured to said second cylinder member,

. said second and third cylinder members each having an effective circumferential surface for supporting said elements and each having a gap providing identical seats for at least the tensioning members of each said first and said second mounting means whereby said second and third cylinder members may interchangeably receive the tensioning members of said first and said second mounting means to enable print-receiving material to be printed at the printing zone from a selected one of said elements and ink to be transferred from said ink rollers to said selected one of said elements by the other of said elements.

2. The invention set forth in claim 1 wherein means is provided in the gap of each of said second and third cylinder members tor cooperating with said rotatable member in the tensioning of a flexible blanket element held thereby.

3. The invention set forth in claim t1 wherein each of said first mounting means and said second mounting means is carried by individual frame means, and wherein the identical seats in said gaps interchangeably receive said individual frame means.

4. A three-cylinder convertible printing unit having first, second and third cylinder members arranged for rotation about three parallel axes for printing either directly -firom a flexible printing plate or by offset from a flexible compressible blanket,

an inker having ink rollers,

said first cylinder member being arranged to support print-receiving material passing through a printing zone,

first mounting means constructed to releasably receive the ends of a flexible, substantially incompressible lprinting plate element and including a member movable tor tensioning said printing plate element,

second mounting means constructed to releasably receive the ends of a flexible, compressible blanket element and including a member rotatable on an axis parallel to the cylinders for tensioning said blanket element,

and means on each of said second and third cylinder members for releasably securing the tensioning member of either said first or second mounting means thereto,

said second and third cylinder members each having an eifective circumferential surface for supporting said elements and each having a gap providing identical seats for said tensioning members whereby said second and third cylinder members may interchange ably receive said tensioning members to enable printreceiving material to be printed in the printing zone from a selected one of said elements and ink to be transferred from said ink rollers to said selected one of said elements by the other of said elements.

5. A convertible printing press having a three-cylinder printing unit for printing either directly from a flexible printing plate or by offset from a flexible compressible blanket onto print-receiving material, comprising an impression cylinder;

an intermediate cylinder adapted to run in rolling contact with the impression cylinder;

a third cylinder adapted to run in rolling contact with the intermediate cylinder, each of said intermediate and third cylinders having a gap therein;

means for mounting the ends of a flexible compressible blanket in one and for mounting the ends of a flexible substantially incompressible printing plate in the other of the gaps of said intermediate and third cylinders, said mounting means including a leading edge clamp on each of said intermediate and third cylinders (for receiving and holding one end of either the blanket or the plate, a trailing edge plate clamp for receiving a printing plate, said trailing edge plate clamp including means for bodily moving the clamp to tension a plate held thereby, a rotatable reel rod for receiving the trailing end of a blanket, said reel rod including means for rotating the rod including means for rotating the rod to tension a blanket held thereby and for locking it in a (preselected position;

and identical seat means in each of said gaps for interchangeably mounting the trailing edge plate clamp and the reel rod on the intermediate and third cylinders.

6. A convertible printing press having a three-cylinder printing unit for printing either directly from a flexible printing plate or by offset from a [flexible compressible blanket onto print-receiving material, comprising an impression cylinder;

an intermediate cylinder adapted to run in rolling cntact with the impression cylinder;

21 third cylinder adapted to run in rolling contact with the intermediate cylinder, each of said intermediate and third cylinders having a gap therein;

means for mounting a flexible compressible blanket by means of blanket bars carried by the ends thereof in the gap of one of said intermediate and third cylinders and for mounting a flexible substantially incompressible printing plate in the gap of the other of said intermediate and third cylinders, said mounting means including a leading edge clamp on each of said intermediate and third cylinders for receiving and holding either a leading edge bar of the blanket or a leading edge of a plate, a trailing edge plate clamp for receiving the printing plate, said trailing edge plate clamp including means for bodily moving the clamp to tension a plate held thereby, a rotatable reel rod having means for receiving a blanket bar at the trailing end of a blanket, said reel rod including means for rotating the rod to tension a blanket held thereby and locking it in preselected positions;

and identical seat means in each of said gaps for interchangeably mounting the trailing edge plate clamp and the reel rod on the intermediate and third cylinders.

References Cited by the Examiner UNITED STATES PATENTS EUGENE R. CAPOZIO, Primary Examiner.

ROBERT A. LEIGHEY, ROGERT E. PULFREY, L.

W. VARNER, WILLIAM PENN, Examiners. 

1. A THREE-CYLINDER CONVERTIBLE PRINTING UNIT HAVING FIRST, SECOND AND THIRD CYLINDER MEMEBRS ARRANGED FOR ROTATION ABOUT THREE PARALLEL AXES FOR PRINTIGN EITHER DIRECTLY FROM A FLEXIBLE PRINTING PLATE OR BY OFFSET FROM A FLEXIBLE COMPRESSIBLE BLANKET. ANN INKER HAVING INK ROLLERS, SAID FIRST CYLINDER MEMBER BEING ARRANGED TO SUPPORT PRINT-RECEIVING MATERIAL PASSING THROUGH A PRINTING ZONE, FIRST MOUNTING MEANS CONSTRUCTED TO RELEASABLY RECEIVE SOLELY THE ENDS OF A FLEXIBLE, SUBSTANTIALLY INCOMPRESSIBLE PRINTING PLATE ELEMENT AND INCLUDING A MEMBER MOVABLE FOR TENSIONING AN END OF SAID PRINTING PLATE ELEMENT, SECOND MOUNTING MEANS CONSTRUCTED TO RELEASABLY RECEIVE SOLELY THE ENDS OF A FLEXIBLE, COMPRESSIBEL BLANKET ELEMENT AND INCLUDING A MEMBER ROTATABLE ON AN AXIS PARALLEL TO THE CYLINDERS FOR TENSIONING ANN END OF SAID BLANKET ELEMENT, MEANS ON SAID SECOND CYLINDER MEMEBR FOR SECURING THERETO AT LEAST THE TENSIONING MEMBER FOR EITHER SAID FIRST OR SAID SECOND MOUNTING MEANS FOR MOVEMENT ABBOUT THE AXIS OF SAID SECOND CYLINDER MEMBER, WITH THE CORRESPONDING ELEMENT RECEIVED THEREBY BEING ADAPTED TO RUN IN ROLLING CONTACT WITH THE PRINT-RECEIVIDNG MATERIAL AT SAID PRINTING ZONE WHILE SUPPORTED BY SAID FIRST CYLINDER MEMBER, 